Illumination control apparatus



July 10, 1934. E B KIRK 1,965,65 4

ILLUMINATION CONTROL APPARATUS Filed June 26, 1951 4 Sheets-Sheet E. B. KIRK ILLUMINATION CONTROL APPARATUS Filed June 26, 1951 4 Sheets-Sheet 2 July 10, 1934.

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Il ilneou' 4 Sheets-Sheet 3 E. B. KIRK ILLUMINATION CONTROL APPARATUS Filed June 26, 1931 July 10, 1934.

I Wiineau' July 10, 1934. E. B. KIRK I ILLUMINATION CONTROL APPARATUS Filed June 26, 1951 4 Sheets-Sheet 4 11125 I biy/ v 176 110 k j enior w FM l l I Wibzeav Patented July 10, 1934 UNITED STATES PATENT OFFICE 7' Claims.

The present invention relates to illumination control apparatus.

In obtaining variable lighting effects for theaters and the like, it is necessary to control the 5 illumination of lamps of different colors by independent dimmers. Because of the large number of dimmers used in some scenes, it is frequently necessary to employ a number of operators, but since the manipulation depends upon the personal element, perfect coordination can rarely be secured. Group actuation of the dimmers may insome cases be permissible when changes in all colors are made at the same rate, but is of only limited application when complicated lighting eilectsare to be produced.

The object. of the present invention is to provide an illumination control system whereby changes in lighting can be effected smoothly from predetermined settings and with capacity 20 for exact repetition of effects.

Withthis object'inlview, the principal feature ofv the present invention comprises the combination of independent dimming units with means for presetting each unit for both initial and final degrees of dimming, andmeans for actuating the several dimming units in unison, but at different rates, depending upon the difference between the initial. and final adjustment of each. By this construction, the: several. dimmers are preset and 30' all are'simultaneously actuated'in such a manner that. all dimmers cover the entire range from initial to final settings in the same time interval. Since the apparatus, after. being once set, fixes the coordination between the units, the variations proceed smoothly throughout the whole range. Moreover, it is possible to obtain a greater flexibility than with the ordinary group actuation system; because-it is not necessary that all dimmers 'work at the same rate or even in the same 4 3 direction; in fact the dimmers usually proceed at different rates and frequently in opposite directions, that'is, with some dimming up and others dimming down.

Other features-f the invention consist of certain novel features of construction, combinations and arrangement of parts hereinafter-described and particularly defined in the claims.

In'the drawings, Fig. 1" is an isometric view of the preferred construction of thepresent invenr. tion; Fig. 2 is a sectional elevation; Fig. 3 is a detail of the setting-mechanism; Fig. 4 is a detail view of the stop operating mechanism; Fig. 5 is a side view of one of'the racks of the stop operating mechanism; Fig; 6 is an end view of the stopxoperating mechanism; Fig. '7 is a detail plan Vl8W of the lock release; Fig. 8 is an end view of the lock release; and Fig. 9 is a graph of the developments of the cams, illustrating the sequence of operations.

The illustrated embodiment of the invention carried on a rod 16 which connects with the opcrating sector 18. The sector is rotatable on a shaft 19. The sector has a handle 20 by which the dimmer may be manually operated.

For automatic control, each dimmer is operated by an oscillating cradle 22 supported on studs 24 and 25 at opposite ends. The cradle has a plurality of toothed bars 26, one for each dimmer. Connectedwith each bar 26 is alink 28 having at its lower end a rack 30 which is caused to engage a pinion 32 connected to the contact arm. The rack is permitted to slide in a bracket 33 adjacent tothe pinion. When the rack and pinion are engaged and the cradle is oscillated, the contact arm will be moved through an are determined by the point of con nection of the link 28 on the toothed bar 26 of the cradle. Thus, if the link is connected at the center of the bar, it will undergo nomovement; if connected at the left' of the center, as shown in Fig. 2, the contact arm will move counterclockwise upon acounterclockwlse oscillation of the cradle; and if connected to the right of the center, the arm will move clockwise. The maximum limits of oscillation of the cradle are shown in dot-and-dash lines in Fig. 2. The cradle is oscillated. by a cam follower 34 engaging a cam 38 on a cam shaft 40. The follower is pressed against the cam by a spring 41 attached between the cradle and the machine frame. The cam shaft is connected by a worm drive 42 with a drive shaft 44 which is rotated by a hand wheel 46. All of the dimmers are independently connected to toothed bars 26 of the cradle. The position of the connection of the link 28 of each dimmer to its corresponding bar is determined in the following manner:0n the shaft 19 adjacent to the sector l3is a rotatable collar 48 which may be rotated by an arm 50 having a presetting handle 51. The handle is spring-pressed to permit it to engage at any point in an arcuate detent member 52. Fixed to the collar is a link 54, and pivoted to this link is a link 56. Pivoted to the sector 18 is a link 58 parallel to the link 56. The links 56 and 58 are connected by a link 60'. It will be seen that the position of the center 61 of the link is determined by the difference in setting between the operating handle 20 and the presetting handle 51. As shown in Fig. 3, the handles 20 and 51 are in the same position, and the point 61 may be said to be in its neutral position. The zero position of the point 61 obtains whenever the two handles are in the same position. If the handles 20 and 51 were moved in unison from the full line position to any other position, the point 61 would not change, although the angular position of the link would change. When the two handles are in different positions, the point 61 is moved from its neutral position in one direction or the other, depending on whether the handle 20 is above or below the handles 51, as shown in dash lines in Fig. 3. A second preset system is shown in dot-and-dash lines in Fig. 2, this system also having a preset handle 62, and an independent set of links, including a link 64 which takes a position dependent on the angular difference in setting between the handle 20 and the preset handle 62.

Connected to the point 61 of the link 60 is a sliding rod 66, which passes through a bearing 68. A sleeve '70 connects with the rod 66 and has provision for a small amount of rotative movement with respect thereto through a pin and slot connection '72. The sleeve connects slidingly with a rod '74 through a longitudinal pin and slot connection '76. The rod 74 has near its end a pinion '78 engaging a sliding rack 80. The sleeve lies closely adjacent to the dimmer operating link 28. The sleeve carries a stop 82, which in vertical position is clear of the link, but in horizontal position lies directly in the path of the link. The stop is placed either in horizontal or vertical position by movement of the rack 86 which is operated by mechanism to be later described in detail.

Similarly, the second preset link is connected with a sleeve which is similar to the sleeve 70, but lies on the opposite side of the link. and car ries a stop 84. The stop 84 is controlled by a pinion 86 engaging a rack 88. The stops 82 and 84 and their connected mechanism are independent of each other, and are employed to permit presetting of two different effects. The two preset mechanisms are independently operated, as will hereinafter be described.

Referring to the first preset mechanism, it will be seen that the position of the stop 82 is determined by the position of the middle point 61 of the link 60, which in turn is determined by the difference in setting between the handles 20 and 51. The handle 20 follows the operation of the dimmer, and the preset handle 51 is set to a position to determine the final position of the dimmer. The handle 20 is therefore set for the desired initial adjustment of the dimmer, and the handle 51 is set for desired final adjustment.

With the cradle in horizontal position, as shown in full lines in Fig. 2, and with the stop 82 in vertical or inactive position. the operating links 28 of all the dimmers are moved to one side of the cradle, all of the stops are then turned into horizontal position, and the links are permitted to move back against their respective stops. During this operation, the toothed bars 26 are in ti to hold the links, but after the links come to rest against the stops. the bars are actuated to engage the links, and then the stops 82 are released. This places each link 28 under the control of the cradle, at a position determined by the position of the stop 82. The cradle is then raised to the upper position indicated at 22 in Fig. 2, and then the rack 30 on each link is caused to engage the pinion 32, so that upon oscillation of the cradle to its lower position 22', the contact arm is retated through a distance determined by the difference in original setting between the handles 20 and 51.

Before describing the mechanism for positioning the operating links 28, the means for connecting them to their bars 26 will be described. Each bar 26 is pivoted at its ends on opposite sides of the cradle. Each bar has at one end a pinion 90, all of the pinions engaging with a rack 92 which is slidingly mounted on the side of the cradle. Adjacent to each bar is a rod 94 on which slides a block 96. The upper end of the operating link 28 is pivoted to the block 96. A detent finger 98 is pivoted on the block and is urged toward horizontal position by a spring 100. The rack 92 terminates in a rod 102 extending through the end of the cradle, and this rod is adapted to be pushed rearwardly by a bellcrank 104 having a cam follower 106 engaging the face of a cam 188. When the rod is pushed rearwardly, the rack rotates the pinions 90, thus bringing the toothed bars from their horizontal position, shown in Fig. 1, to a vertical position, as shown in Fig. 2. The rack is held in its rearward position by a spring-pressed latch arm 11o (Figs. '7 and 8) pivoted on the inside of the cradle, and engaging in a slot 112 in the rod 102. The latch is released at the end of the oscillation of the cradle by a pin 114 upstanding from the frame and adapted to strike the latch as the cradle approaches the position 22*, the rack be-- ing then restored to original position by tension springs 115 connected between the rack and the cradle.

The mechanism for positioning the link 28 with respect to its bar 26 will now be described. Assume the stop 82 to be in proper position, determined by the difference in setting between the handle 20 and the preset handle 51, the cradle to be in horizontal position, and the bar 26 to be down, as shown in Fig. 1. Then the operating links 28 are all simultaneously moved to the right-hand side of the cradle by means of a set of sweeper arms 116. all of which are mounted on a rocker shaft 118 above the cradle. The shaft is oscillated by a cam follower 120 engaging the edge of a cam 121. Each sweeper has a pin 122 to engage its corresponding link 28. The sweepers are then moved back to their original or left-hand positions, by a torsion spring 124 on the shaft 118, but prior to the movement of the sweepers, the stops 82 are turned from inactive (vertical) to active (horizontal) position by movement of the rack 80. Thus, when the sweepers are released, each link 28 follows its sweeper under the action of a spring 130 until it strikes its stop 82. It is at this time that the rack 92 works to turn the toothed bars 26 into locking position to engage the detent fingers 98 on the upper ends of the operating links. It is immaterial if the finger fails to be engaged between teeth of the bar; the finger cannot move more than a short distance either way without falling into locking position. The operating link being now under the control of the locking bar, the stop 82 is rendered inactive by a return movement of the rack under the action of the cam 128. The operating links 28 are now connected at their proper positions to the cradle.

The cradle now moves quickly to its upper position 22 by the action of the cam 38. Thus far the: rack 30 on the operating link has been disengaged from the pinion 32, so that the link. has been free to undergo the motions above described, without moving the dimmer contact arm. When the cradle reaches its upper position, the rack is engaged by the pinion in the following manner:- On the cam shaft 40 is a cam 132 which engages a cam follower 134 connected by a rod 136 to an arm 138 secured to a rock shaft 140. On the rock shaft 140 is a rotatable cam 142 engaging one arm of a bell-crank 144 pivoted on a bracket 146. The other arm. of the bell-crank is pivoted to an arm 148 which embraces at its end a rod 150 and bears against a collar 152 on the rod. A compression spring 154 encircles the rod and bears between the collar and the bracket. The rod is journaled at opposite ends, and at an intermediate point 155 is pivotally connected to the rack bracket 33. When the bell-crank 144 is lifted by the cam 142, the rack is disengaged from the pinion, but when the cam is rotated to permit the bell-crank to drop, the rack 30engages with the pinion 32. The operating links 28 being now operatively connected with their dimmers, the cradle is oscillated from its upper position 22 through an arc of about 60 to its lower position 22*, under the control of the cam 38. This movement of the cradle operates the dimmers, each at a rate dependent upon the position of connection of its operating link 28to the corresponding toothed bar 26. Dur ing this movement, the contact arms of the dimmers are rotated, and this rotation is transmitted through the connections 16 to the sector 18, thus continuously moving the operating handle 20. When the cradle assumes its final position, the operating handle 20 comes into line with the preset handle 51, no matter what the relative positions of the two handles were at the beginning of the operation.

As the cradle approaches its lower position, the locking bars 26 are unlocked from the operating links by the release of the latch 110 occasioned by strikingthe release pin 114. At approximately the same time, the dimmer clutch (that is, the rack 30 and the pinion 32) is disengaged by the cam 132 operating through the earn 142 and bell crank 144; The cradle is then restored to horizontal position by action of the cradle cam 38. This completes the cycle of operations.

The invention as described above employs two preset mechanisms, one being operated by the handle 51, and the other by the handle 62. These preset mechanisms are independent of each other, and are preferably employed in succession, so that two complete illumination effects can be preset upon the apparatus. These two'mechanisms are independently operated through the racks 80and'88 which independently control the stops 82 and 84 respectively. Both of the racks 80 and 88 are adapted for selective operation by a cam 169 on the shaft 40, and the means by which the selection is made is described as follows:--The cam 169 comprises two cam members 170 and 172 spaced at different distances from the axis of the shaft. A cam follower 174 is adapted to engage the inner surface of the cam 1'70'and the outer surface of the cam 1'72, the two cam faces being spaced only sufficiently far apart to give a short throw to the follower first in one direction and then in the other. The follower 174 comprises a pin projecting from a bell-crank 176,.which is pivoted in a bracket 1'78 journaled in the machine frame. One arm of the bellcrank 175. is adapted to engage in a channel bracket 180 at the end of the rack; 80: or. in' a bracket 182 at the projecting end of the rack88', as showninfull lines anddot-and-dash lines, respectively, inFig. 6. A link .184 connectsthe. arm 1'76 with a bell-crank. control lever 186' which: is provided with a handle 188 projectingthrougha slot 189 in the frame. When the handle188. is in its left-hand:position,.as indicated in Fig. 1,.the bell-crank 176. assumes full line position engaging the rack 80. When the handle is at the. other end of the slot, the bell-crank engages. the rack 88. In. either case, the action of thecam: faces 1570 and 172 is. to! move either therackBOIorthe rack 88 first in one direction orv the other forthe purpose of temporarilyplacing'either thestop'82 or the stop 84 in the-path of the dimmer operating link 28.

The dimmer operating'handles 20 are. placed in the positions which it is desired the dimmers shall have for the beginning of the illumination effect. Assuming now that only a single set. of preset mechanisms is to be employed, the handles 51 are set at the positions for the final. adjust ment of the dimmers, the handle l88lbeing placed at the left-hand end ofthe' slot. This is the only adjustment which is necessary. The hand wheel 46 is then turned, thereby turning the cam shaft 40. The first half revolution of the cam= shaft sets the operating links intolthe positions determined by the differences in settings betweenthe operating handles 20 and the preset handles-51, while approximately the last half of the revolution is set to operate the dimmers. For'the first half revolution, the wheel may be turned very rapidly, but for the last half revolution wherein the actual operation of the dimmers occurs, the wheel may be moved at any'desired rate. Considering the first half'revolution of the cam shaft, the first action is to move the sweepers from left to right, as viewed in Fig. 1', this motion being represented approximately by the first of r0- tation of the sweeper cam 121, as indicated in the cam development of Fig. 9. Immediately upon completion of the movement of the sweepers, the cam face 170 of the rack" operating cam 128 moves the rack into such a position that the active stop 82 is-turneddown into the path of the operating link 28; The sweeper cam then operates to release the sweepers, so that the links 28 are returned under the influence of the springs 130 to a position determined bythe stops 82. Immediately thereafter, the bar: operating cam 108 operates to locktherfingers'98to bars'26, and the cam face 1700f the cam-128operates to lift the stops 82'into inactive position. During this entire period, theicradlecama38is inactive,.but it now operates to raise'the cradle to it'suppermost position 22. This action is indicated in the development by the interval from 150 to 165. From 165 to 180 the cradle cam holdsthecradle motionless, but the clutch cam 132 operates to engage the rack 30 with the pinion 32. The cradle cam then operates to carry the cradle from position 22. to 22' thisinterval runningfrom 180 to 330, as shown on the development. As the cradle approaches its final. position, the toothed bars are unlatched by the stop 114. From 380 to 345 the cradle is held motionless in position 22* and during this interval, the clutch cam 132 operates to disengage the rack 30 from the dimmer operating pinion 32. Inthe interval from 345 to 360 the cradle cam restores the cradle to its horizontal position in preparation for another operation. At the conclusion ofthe operation, all of. the operatingv handles occupy the same positions as their corresponding preset handles 51, if the latter have not been moved during the dimming operation. However, it is not necessary that the preset handles be kept stationary throughout the Whole cycle, because as soon as the stop cam 169 has completed its work, the handles 51 have no further effect upon the operation of the dimmers, and may, if desired, be reset for another lighting effect.

In view of the fact that it may be necessary to run off two effects in quick succession, it may be desirable to preset both of them, and it is for this purpose that the second preset mechanism is provided. The preset handles 51 are set for the first eifect, and the handles 62 are set for the second effect. At the conclusion of the first cycle, therefore, it is only necessary to move the selector handle 188 to its right-hand position, and then to continue rotating the hand wheel. If this is done, the stops 84 will be set for the second cycle, and the dimmers will move from the positions at which they arrive in the first cycle, to the positions determined by the second preset mechanism for the second cycle. By the use of both preset mechanisms, therefore, sufficient time is usually afforded for resetting any desired number of illumination effects during the course of the play. It is sometimes desirable to permit manual operation of one or more dimmers, while permitting the others to be operated automatically, and to this end the dimmer clutch bellcrank 144 is connected with a lever 200 which protrudes through the frame of the machine and is provided with an external handle 202. The handle is free to slide vertically in a slot 204, and is adapted to be retained in its uppermost position by a transverse slot 206. When the handle 202 is in its lowermost position, the bell-crank is under the control of the cam. However, when the handle is raised, it engages an overhanging end 208 of the bell-crank, and raises the latter so that the rack and pinion are disengaged. The particular dimmer may then be manually operated by its handle 20, regardless of automatic operation of the other dimmers.

If desired, the cam shaft may be operated by a motor, but inasmuch as the changes in the illumination generally accompany the spoken words of the play, it is ordinarily preferable to have the system under manual control. The speed at which the wheel should be rotated depends on the judgment of the operator, but this can be easily determined for any desired illumination elfect by proper rehearsals. The operator can give his undivided attention to the manipulation of the wheel, it being unnecessary to consider the interaction of the various lights, since this is all cared for by the automatic operation of the system.

It will be seen that the invention operates to operate the separate dimmers independently at rates substantially proportional to their initial and final settings, as determined by the positioning of the stop 82 (or 84). If the link is in neutral position, so that the link 28 is connected to the middle of the locking bar 26, the link undergoes no operating movement; if at the left of neutral, the contact arm moves counterclockwise; and if at the right of neutral, the contact arm moves clockwise, the rate of movement being substantially proportional to the setting from neutral position. Although the rate of actuation of any dimmer may not be exactly uniform, be-

, cause of the angular motion of the cradle, the

deviation from uniformity is practically negligible.

Although a particular form of the invention has been illustrated and described, it is to be understood that the invention is not limited to the precise construction herein shown. In its broader aspects, the invention comprehends use of dimming devices having provision for indeendent setting of initial and final adjustments, together with means for bringing all dimmers, each at a substantially uniform rate, to their final adjustment simultaneously, or in other Words for operating each dimming device at a rate substantially proportional to the difference in setting between the initial and final adjustments.

Having thus described the invention, what is claimed is:

1. An illumination control apparatus having, in combination, a plurality of dimmers, each having a dimmer operating handle, a preset handle for each dimmer, a linkage mechanism connected with the operating handle and the preset handle and having a part positioned in accordance with the difference in setting of the handles, 1 an oscillating member, an operating link for each dimmer, and means for connecting each operating link with the oscillating member at a distance from the axis of the oscillating member corresponding to the setting of said part. 1

2. An illumination control apparatus having, in combination, a plurality of dimmers, each having a dimmer operating handle, a preset handle for each dimmer, a linkage mechanism connected with the operating handle and the preset 1 handle and having a part positioned in accordance with the difference in setting of the handles, a stop connected with said part, an operating link for each dimmer, means for setting the link against the stop, and an oscillating mem- 1 her, each link being permanently connected to the oscillating member but at a position determined by said stop.

3. An illumination control apparatus having, in combination, a plurality of dimmers, an op- 1 erating link for each dimmer, an oscillating member having means for connecting the several operating links thereto, a stop for positioning each operating link, means for setting each stop in accordance with the desired initial and 1 final settings of the dimmer, and means for moving th operating links simultaneously to their extreme positions and returning them, means for placing the stops in their said positions in the paths of the operating links upon the return movement thereof, and means for connecting the operating links to the oscillating members in the positions determined by the stops.

4. An illumination control apparatus having, in combination, a plurality of dimmers, each hav- 1 ing an operating handle and a preset final adjustment handle, a preset mechanism connected with the handles, an oscillating member, an operating link for each dimmer adapted to be connected with the oscillating member, means for 1 simultaneously moving all of the operating links to their extreme positions with respect to the oscillating member and returning them, a stop for each dimmer controlled in position by the difference in setting between the operating and 1 preset handles and disposed in the path of the operating link on the return movement thereof, means for connecting each operating link to the oscillating member at a position from the axis thereof determined by the position of the stop, 1

and means for rocking the oscillating member to operate the dimmers through the operating links.

5. An illumination control apparatus having, in combination, a plurality of dimming devices, each having an operating handle, two preset mechanisms, each having a preset final adjustment handle, means for independently operating the individual dimmers at rates proportional to the difference in setting between the operating handle and either preset handle, and means for shifting control to either set of preset handles.

6. An illumination control apparatus comprising a plurality of dimmers each having an initial adjustment handle and a final adjustment handle, an actuating device, means for moving the actuating device, an operating link for each dimmer permanently connected to the actuating device, and means for varying the point of connection of the operating link to the actuating device in accordance with the difference between the settings of the initial and final adjustment handles of the corresponding dimmer to cause movement of the initial adjustment handle from its initial position into register with the final adjustment handle.

7. An illumination control apparatus having, in combination, a plurality of dimmers each having an operating handle and two preset mechanisms, each preset mechanism having a final adjustment handle, means for independently operating the individual dimmers at rates proportional to the difference in setting between the operating handle and one of the final adjustment handles, said means operating to move the operating handle from its initial position into register with one of said final adjustment handles, and means for independently operating the individual dimmers to move each operating handle from said position into register with the second of said final adjustment handles.

EDWARD B. KIRK. 

